Recently, with the emergence of a large data center, research is ongoing to convert a data center based on an alternating current (AC) power transfer to a data center based on a more efficient direct current power transfer.
In this regard, Korean Patent Laid-Open Publication No. 10-2011-003035, published on Jan. 11, 2011, titled “Direct current (DC) electric power supply system”, discloses technology in which a DC power supply system receives AC power and directly supplies, to a plurality of servers, DC power output from a rectifier configured to generate the DC power.
However, the conventional power supply system uses an individual power supply unit (PSU) for each server. Accordingly, when an error occurs in supplying power due to, for example, an overload, a blackout, the fault of a PSU, it may critically affect a server operation. Also, the power efficiency may vary based on a state of a PSU individually used for each server and thus, it may be difficult to achieve the maximum effect.
Accordingly, there is a need for a method that may prevent a data loss from occurring due to, for example, an overload, a blackout, and the fault of a PSU, and may maintain the power efficiency to be in an optimal state.